1. Power via USB or External Source - 5v or 7-35v (12v or less recommended, automatic selection) 2. On-board 500ma 5V Regulator 3. Built-in USB 4. 26 I/O Pins (2 are used for USB only if your program actively communicates over USB, otherwise you can use all 6 even if you are programming via USB) 5. 8k Flash Memory (about 6k after bootloader) 6. I2C and SPI 7. 26-PWM (26 pins with Software PWM,only two(D9,D10) with hardware PWM ) 8. Support by Arduino IDE Programming Software 9. ADC on 8 pins 10. Power LED and Test/Status LED 11. Size(mm):44.5x18.3x3